Helmut Prosch

Risk factors for diabetes insipidus in langerhans cell histiocytosis

Diabetes insipidus (DI) is the most frequent central nervous system (CNS)‐related permanent consequence in Langerhans cell histiocytosis (LCH), which mostly requires life‐long hormone replacement therapy. In an attempt to define the population at risk for DI, 1,741 patients with LCH registered on the trials DALHX 83 and DALHX 90, LCH I and LCH II were studied.

Langerhans cell histiocytosis in neonates.

To study the incidence, clinical patterns, course, and outcome of neonatal Langerhans cell histiocytosis (LCH).

Central diabetes insipidus as presenting symptom of Langerhans cell histiocytosis.

Central diabetes insipidus (CDI) is a rare disorder associated with various underlying diseases. Among the systemic diseases that may cause CDI, Langerhans cell histiocytosis (LCH) is the most common. Therefore, in patients with endocrinologically proven CDI, a comprehensive diagnostic evaluation is crucial to identify possible extracranial sites of LCH. The goal of the diagnostic evaluation is to yield histopathological proof of the underlying disease. If possible, this histopathological proof should be provided by a biopsy of extracranial lesions to avoid a potentially hazardous biopsy of the pituitary stalk.

Course and clinical impact of magnetic resonance imaging findings in diabetes insipidus associated with Langerhans cell histiocytosis

Diabetes insipidus (DI) is the most frequent sequela in Langerhans cell histiocytosis (LCH). The clinical relevance and therapeutic impact of brain magnetic resonance imaging (MRI) findings in LCH patients with LCH during the disease course is unclear.

Pattern and Course of Neurodegeneration in Langerhans Cell Histiocytosis

OBJECTIVE To explore the frequency and course of neurodegenerative central nervous system (CNS) disease in Langerhans cell histiocytosis (ND-LCH). STUDY DESIGN We studied 83 patients with LCH in whom magnetic resonance imaging (MRI) of the brain was performed at least twice for various clinical indications. We defined radiologic ND-LCH as an MRI pattern comprising bilateral symmetric lesions in the dentate nucleus of the cerebellum or basal ganglia. RESULTS Forty-seven of 83 patients (57%) had radiologic ND-LCH, at a median of 34 months (range 0-16 years) from the diagnosis of LCH. The MRI findings deteriorated in 31/47 (66%) patients over a median of 3 years (range 2 months to 12 years 6 months) and did not reverse in any patient. In 12 patients with radiologic ND-LCH (25%), clinical ND-LCH with overt symptoms were found 3 to 15 years (median 6 years) after initial LCH diagnosis. These symptoms included intention tremor, cerebellar ataxia, dysarthria, dysdiadochokinesis, concentration deficits, psychomotor retardation, severe headaches, and psychosis. CONCLUSION We conclude that radiologic ND-LCH is serious, not uncommon in patients studied by MRI, irreversible, and may be followed by severe clinical ND-LCH many years after the initial diagnosis of LCH.

Evaluation of Diffusion-Weighted MRI for Pretherapeutic Assessment and Staging of Lymphoma: Results of a Prospective Study in 140 Patients

Purpose: To determine the value of diffusion-weighted MRI (DWI-MRI) for pretherapeutic imaging of fluorodeoxyglucose (FDG)-avid lymphoma and lymphoma with variable FDG avidity. Experimental Design: Treatment-naïve patients with lymphoma who were referred for whole-body staging were included in this prospective study. Group A included patients with FDG-avid lymphoma (e.g., Hodgkin, diffuse large B-cell, and follicular lymphoma), whereas Group B included patients with lymphoma of variable FDG avidity [e.g., extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT)]. All patients underwent DWI-MRI and 18F-FDG- positron emission tomography/computed tomography (PET/CT). Region-based sensitivity and agreement with Ann Arbor staging, relative to the reference standard, were calculated for DWI-MRI, and, in Group B, also 18F-FDG-PET/CT and contrast-enhanced (CE-) CT. Results: In Group A (100 patients), DWI-MRI had a region-based sensitivity of 97%, and with regard to staging, agreed with the reference standard in 94 of 100 patients (κ, 0.92). In Group B (40 patients; 38 MALT lymphomas and 2 small lymphocytic lymphomas/chronic lymphocytic leukemias), DWI-MRI, 18F-FDG-PET/CT, and CE-CT had region-based sensitivities of 94.4%, 60.9%, and 70.7%, respectively. With regard to staging in Group B, DWI-MRI, 18F-FDG-PET/CT, and CE-CT agreed with the reference standard in 37 of 40, 26 of 40, and 24 of 40 patients, with κ values of 0.89, 0.52, and 0.43, respectively. Conclusions: In patients with FDG-avid lymphoma, DWI-MRI seems to be only slightly inferior to 18F-FDG-PET/CT with regard to pretherapeutic regional assessment and staging. In patients with lymphoma subtypes that show a variable FDG avidity (e.g., MALT lymphoma), DWI-MRI seems to be superior to both 18F-FDG-PET/CT and CE-CT. Clin Cancer Res; 20(11); 2984–93. ©2014 AACR.

Central nervous system-related permanent consequences in patients with Langerhans cell histiocytosis.

Permanent consequences in Langerhans cell histiocytosis (LCH) are irreversible late sequelae related to the disease that may severely impair the quality of life of survivors. The frequency and pattern of permanent consequences affecting the central nervous system (CNS) remains to be determined.

Evaluation of Diffusion-weighted Magnetic Resonance Imaging for Follow-Up and Treatment Response Assessment of Lymphoma: Results of an 18F-FDG-PET/CT-controlled Prospective Study in 64 Patients

Purpose: To determine the value of diffusion-weighted MRI (DWI-MRI) for treatment response assessment in 2-[18F]fluoro-2-deoxy-D-glucose (FDG)–avid lymphoma. Experimental Design: Patients with FDG-avid Hodgkin (HL) or non-Hodgkin lymphoma (NHL) at pretherapeutic 18F-FDG-PET/CT, who had also undergone pretherapeutic whole-body DWI-MRI, were included in this prospective study. Depending on the histologic lymphoma subtype, patients received different systemic treatment regimens, and follow-up DWI-MRI and 18F-FDG-PET/CT were performed at one or more time points, depending on the clinical course. For each follow-up DWI-MRI, region-based rates of agreement, and rates of agreement in terms of treatment response (complete remission, partial remission, stable disease, or progressive disease), relative to the corresponding 18F-FDG-PET/CT, were calculated. Results: Sixty-four patients were included: 10 with HL, 22 with aggressive NHL, and 32 with indolent NHL. The overall region-based agreement of DWI-MRI with 18F-FDG-PET/CT was 99.4%. For the 51 interim examinations (performed after 1–3 therapy cycles), region-based agreement of DWI-MRI with 18F-FDG-PET/CT was 99.2%, and for the 48 end-of-treatment examinations, agreement was 99.8%. No significant differences, in terms of region-based agreement between DWI-MRI and 18F-FDG-PET/CT, were observed between the three lymphoma groups (HL, aggressive NHL, indolent NHL; P = 0.25), or between interim and end-of-treatment examinations (P = 0.21). With regard to treatment response assessment, DWI-MRI agreed with 18F-FDG-PET/CT in 99 of 102 follow-up examinations (97.1%), with a κ value of 0.94 (P < 0.0001). Conclusions: In patients with FDG-avid lymphoma, DWI-MRI may be a feasible alternative to 18F-FDG-PET/CT for follow-up and treatment response assessment. Clin Cancer Res; 21(11); 2506–13. ©2015 AACR.

CT fluoroscopy-guided vs. multislice CT biopsy mode-guided lung biopsies: Accuracy, complications and radiation dose

BACKGROUND The aim of this retrospective study was to compare the diagnostic accuracy, the frequency of complications, the duration of the interventions and the radiation doses of CT fluoroscopy (CTF) guided biopsies of lung lesions with those of multislice CT (MS-CT) biopsy mode-guided biopsies. METHODS Data and images from 124 consecutive patients undergoing CTF-guided lung biopsy (group A) and 132 MS-CT-biopsy mode-guided lung biopsy (group B) were reviewed. CTF-guided biopsies were performed on a Siemens Emotion 6 CT scanner with intermittent or continuous CT-fluoroscopy, MS-CT biopsy mode-guided biopsies were performed on a Siemens Emotion 16 CT scanner. All biopsies were performed with a coaxial needle technique. RESULTS The two groups (A vs. B) did not differ significantly regarding sensitivity (95.5% vs. 95.9%), specificity (96.7% vs. 95.5%), negative predictive value (87.9% vs. 84%) or positive predictive value (98.8% vs. 98.9%). Pneumothorax was observed in 30.0% and 32.5% of the patients, respectively. Chest tube placement was necessary in 4% (group A) and 13% (group B) of the patients. The duration of the intervention was significantly longer in group A (median 37 min vs. 32 min, p=0.04). The mean CT dose index (CTDI) was 422 in group A and 36.3 in group B (p<0.001). CONCLUSION Compared to CTF-guided biopsies, chest biopsies using the MS-CT biopsy mode show dramatically lower CTDI levels. Although the diagnostic yield of the procedures do not differ significantly, biopsies using the MS-CT-biopsy mode have a three-fold higher rate of chest tube placement.

Long-Term MR Imaging Course of Neurodegenerative Langerhans Cell Histiocytosis

BACKGROUND AND PURPOSE: MR imaging signal intensity abnormalities in the cerebellum, the pons, and the basal ganglia, compatible with a neurodegenerative process (ND) were reported in up to 10% of patients with Langerhans cell histiocytosis (LCH). Although the imaging features of ND-LCH have been extensively described, the temporal course of ND-LCH has not been assessed as of yet. The purpose of this study was to describe the long-term course of MR imaging signal intensity abnormalities in ND-LCH on T1- and T2-weighted images. MATERIALS AND METHODS: In this retrospective study, 9 patients with ND-LCH with an observation time of at least 5 years were included. Three or more MR imaging studies per patient, performed in 3-year intervals (±11 months), were reviewed. Signal intensity abnormalities on T1- and T2-weighted images in the cerebellum, the pons, and basal ganglia were scored for their signal intensity quality and their extension. In addition, the severity of cerebellar atrophy was scored. RESULTS: The signal intensity alterations were not resolved in any of the patients. Instead, a progression of the signal intensity alterations either in the cerebellum or basal ganglia was observed in all of the patients but did not correlate with a clinical deterioration. Overt and severe neurologic symptoms were reported in only 2 patients in whom some form of atrophy was noted. CONCLUSIONS: ND-LCH appears to be a slowly progressive process. The increase of signal intensity abnormalities in the cerebellum and basal ganglia does not correlate with neurologic deterioration. MR imaging appears to be a sensitive technique to detect and monitor radiologic ND-LCH.